Severe flooding and drought caused by extreme weather patterns lead to about 10,000 deaths and US$40 billion in damage a year, with the number and extremity of the events is slated to increase in the future. The agricultural sector is particularly vulnerable.

In an era of rampant land development and increasing climate unpredictability, the world is growing used to alarming images of flooded city streets. But cities can combat these floods by turning themselves into "sponge cities".